locking/rwsem: Reinit wake_q after use

In __rwsem_down_write_failed_common(), the same wake_q variable name
is defined twice, with the inner wake_q hiding the one in outer scope.
We can either use different names for the two wake_q's.

Even better, we can use the same wake_q twice, if necessary.

To enable the latter change, we need to define a new helper function
wake_q_init() to enable reinitalization of wake_q after use.

Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1485052415-9611-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Waiman Long
2017-01-21 21:33:35 -05:00
committed by Ingo Molnar
parent 06321dd2d1
commit bcc9a76d5a
2 changed files with 11 additions and 2 deletions

View File

@@ -1021,6 +1021,12 @@ struct wake_q_head {
#define DEFINE_WAKE_Q(name) \
struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
static inline void wake_q_init(struct wake_q_head *head)
{
head->first = WAKE_Q_TAIL;
head->lastp = &head->first;
}
extern void wake_q_add(struct wake_q_head *head,
struct task_struct *task);
extern void wake_up_q(struct wake_q_head *head);